The sidewall markings on a tire provide descriptive information about the tire’s design.
Step by step let’s interpret the sidewall markings on the tire image example below by reading clockwise from P215/65R16, which is located on the lower left-hand corner of the tire illustration:
P – Passenger vehicle tire
215 – This number specifies the width in millimeters (i.e. 215 mm)
65 – This number is the Aspect Ratio, the ratio of sidewall height to width
R – Radial
16 – This number designates the tire’s diameter in inches (i.e. 16″)
89 – This number indicates the tire’s load-carrying capacity, known as the Load Index; as the number for the load index increases so does the load-carrying capacity (All passenger car tires in the U.S. are also marked with their actual load limit in pounds)
H – This letter denotes the Speed Rating, the maximum tire speed under controlled test conditions (H” in this example is one of several types of speed ratings)
Treadwear – Wear rate of the tire determined by field testing following a government specified course
Traction – How well the tire stops on wet roads in government tests, graded using the letters AA, A, B, or C with AA being the highest in performance
Temperature – The tire’s resistance to the heat generated by running at a high speed in government tests, which is also graded using A, B, or C with A being the best
psi (pounds per square inch) – The maximum cold inflation rating for the tire
DOT (Department of Transportation) – This symbol indicates the tire meets or exceeds United States DOT safety standards; the letters and numbers following the DOT symbol provide information about the tire manufacturer, tire size, and the date it was manufactured
For information on tire size and pressure specific to your vehicle please refer to Tires in the index of your owner’s manual for the appropriate page numbers. Additional tire information is also available in the tire section of the DOT website.